The present invention relates to an electrical connecting structure of a printed substrate.
With the recent tendency of miniaturization of electronic appliances, flexible printed substrates have been widely used. The flexible printed substrate is electrically connected by means of a contact structure using thermocompression bonding with a well known anisotropic conductive bond.
Such a contact structure is disclosed, for example, in Jpn. Pat. Appln. KOKOKU publication No. 8-12352. The disclosed contact structure has a connecting terminal electrode at the connecting portion between a flexible printed substrate and an LCD-mounting substrate or at the connecting portion between flexible printed substrates, and the bonding strength of the substrates is increased by dividing the contact electrode into two in a recess form.
However, the connecting structure formed by means of thermocompression bonding using anisotropic conductive bond set forth in the publication has a problem in that repair cannot be made when the flexible printed substrate fails in thermocompression bonding. In other words, only one type of connecting terminal is prepared for each usage as the connecting terminal to be formed on the regularly-employed flexible printed substrate, so that if the contact terminal fails in thermocompression bonding, the substrate must be discarded as a useless article.
However, since there are many cases in which an expensive electronic part such as a microprocessor is attached to the flexible substrate, costs may increase if the expensive electronic part is discarded every time the connecting terminal of the substrate fails in thermocompression bonding.